large glowing orb 4.5k feet above ground NW of Chicago last night 9:30pm

Last night my partner and i stepped onto our 8th floor apartment balcony which is on the south west side of Chicago. we were watching planes fly to ohare and midway when i noticed a large glowing orb. It was hovering completely still in the air around 3-5k feet if my estimate is close. My partner said that he thought it was Mars or another planet. However the location did not match up with any planets or bright stars in the area. It was about 1.5x larger than seeing mars with the naked eye an...